<p><b>OBJECTIVE</b>To explore activity laws of mitochondrial complex II in patients of deficiency-cold syndrome (DCS) and deficiency-heat syndrome (DHS) under various ambient temperatures.</p><p><b>METHODS</b>Subjects were recruited by questionnaire and expert diagnosis from grade 1 - 3 undergraduates at Henan College of Traditional Chinese Medicine in November 2012, and assigned to a normal control group, the DCS group, and the DHS group, 20 in each group. Their venous blood samples were collected at two different temperature conditions. Activities of mitochondrial complex II were measured by spectrophotometry.</p><p><b>RESULTS</b>(1) Comparison of mitochondrial complex It under various ambient temperatures: Compared with room temperature in the same group, activity values were all increased in the normal control group at cold temperature with significant difference (P <0.05), but there was no significant difference in the DCS group and the DHS group (P >0. 05). Compared with the normal control group, activity values of complex H were reduced in the DCS group at cold and room temperatures with significant difference (P <0.05). Compared with the DCS group, activity values of complex It were increased in the DHS group with significant difference (P <0. 05). (2) Changes of adjustment rates: Compared with room temperature, the adjustment rate all rose at cold temperature in the normal control group and the DHS group with significant difference (P <0.05), but with no significant difference found in the DCS group (P >0. 05). Compared with the normal control group at the same temperature, the adjustment rate in the DHS group and the DCS group was all reduced at cold and room temperatures with significant difference (P <0. 05). There were no significant difference in the adjustment rate between the DHS group and the DCS group (P > 0. 05).</p><p><b>CONCLUSIONS</b>Environment temperature can affect the activity of mitochondrial complex II with different influence degrees on different syndrome types of people, but its change trend are basically identical.</p>